1. Field of the Invention
This invention relates to lubricating oils containing borated detergent additives which inhibit rust, corrosion and deposits of fuels and lubricating oils resulting from the accumulation in engines of the oxidation and degradation products. More specifically, this invention discloses an improved process for preparing borated detergent additives for use in lubricants.
When mineral lubricating oils are employed as crankcase lubricants in internal combustion engines, fuel and lubricant oxidation and degradation products accumulate in the lubricant and impinge on the engine surfaces with the resultant formation of gums, sludges which clog the oil feed lines and varnish-like deposits on the surfaces of rings, pistons, cylinders and other engine parts. Further, with emission control devices being installed on the presently manufactured automotive vehicles, some of the corrosive bodies of the engine exhaust system are introduced into the crankcase oil. The gums and sludges lead to piston sticking and varnish on the cylinder walls. This, coupled with the attack of the corrosive bodies on the engine metal surfaces, cause substantial deterioration of the engine operation.
In order to counteract these negative factors, additives are added to crankcase oils in small amounts such as dispersants and detergents to counteract the formation of gums and sludges and anticorrosives to inhibit the corrosive action of the exhaust gases introduced into the crankcase system, as well as rust inhibitors to prevent rust formation on engine metal parts.
2. Disclosure Statement
U.S. Pat. No. 3,480,548 discloses a process for preparing a borated, overbased metal detergent which process utilizes an overbased metal detergent in reaction with boric acid at a very high temperature of 150.degree.-175.degree. C.
U.S. Pat. No. 3,679,584 discloses a process which utilizes that of U.S. Pat. No. 3,480,548 to prepare a borated intermediate which is subsequently overbased further.
U.S Pat. No. 3,829,381 discloses a process similar to that of U.S. Pat. No. 3,480,548 whereby an overbased metal detergent is produced.
U.S. Pat. No. 3,909,691 discloses a borated overbased alkaline earth metal sulfonate prepared by a process similar to that of U.S. Pat. No. 3,480,548 where the overbased earth metal sulfonate is then treated with an alkali metal base.
U.S. Pat. No. 4,683,126 discloses the preparation of an alkaline earth metal borate dispersion in a sulfonate by in situ reaction of a metal oxide or hydroxide with boric acid in the presence of water and a hydrocarbon solvent.
U.S. Ser. No. 833,689 discloses a lubricating oil composition which has improved properties of inhibiting rust, corrosive and deposit formation. The improved properties are imparted by the addition of minor amounts of a metal salt of an alkenylsuccinamic acid.